ILLUSTRATIONS IX 



27. Autosomal inheritance, results of mating 



dominant and recessive parents 106 



28. Results of mating two Fi heterozygotes 108 



29. Results of mating dominant and recessive 



parents, differing in two pairs of autosomes 1 16 



30. Results of putting together two chromo- 



somes defective in different ways 133 



31. Different results of placing together two de- 



fective chromosomes 135 



32. Results of crossing-over 140 



33. Arrangement of genes in linear series 146 



34. Crossing-over 149 



35. Certain relations in crossing-over 151 



36. Arrangement of genes in the genetic system 157 



37. Structure of chromosomes 159 



38. Maps of the four chromosomes of Droso- 



phila 161 



39. Results of linkage with relation to gametes 170 



40. Proof that a gene is in the fourth chromo- 



some 173 



41. Map of eye-color genes of Drosophila 184 



42. Loss of parts of chromosomes in Ascaris 189 



43. Method of testing for a deficiency 195 



